It is well known to use ice to cool, for example, beverages. Traditional coolers having insulated sidewalls and an insulated lid are typically shipped and sold in a fully-assembled configuration. Generally, the insulated sidewalls of a standard cooler are semi-rigid and cannot be collapsed to place the cooler in a flattened configuration for shipping or handling. Although some soft-sided coolers have been manufactured, they too have disadvantages. Existing soft-sided coolers do not pack as flat as may be desired, and they are relatively expensive. Thus, it remains desirable to have a relatively inexpensive, collapsible cooler.